The Fluke Model 175, Model 177, and Model 179 are batterypowered, true-RMS multimeters (hereafter "the Meter") with a 6000-count, 3 3/4-digit display and a bar graph. This manual applies to all three models. All figures show the Model 179. These meters meet CAT III and CAT IV IEC 61010 standards. The IEC 61010 safety standard defines four overvoltage categories (CAT I to IV) based on the magnitude of danger from transient impulses. CAT III meters are designed to protect against transients in fixed-equipment installations at the distribution level; CAT IV meters are designed to protect against transients from the primary supply level (overhead or underground utility service). The Meter measures or tests the following: ¨ AC / DC voltage & current ¨ Diodes ¨ Resistance ¨ Continuity ¨ Voltage & frequency ¨ Capacitance ¨ Temperature (Model 179 only)